An everting catheter typically includes an outer catheter having an outer catheter lumen and an inner catheter movable longitudinally in the outer catheter lumen and having an inner catheter lumen. An everting element is coupled to the outer catheter and the inner catheter so that, with movement of the inner catheter distally in the outer catheter lumen, the everting element can be everted through an opening in the outer catheter.
An everting catheter of this type can be inserted through a passage in the human body with the everting element in an inverted position. An elongated, flexible instrument can then be introduced through the inner catheter lumen and the everting element to position the instrument into a desired body region and accomplish any of a variety of medical procedures and/or viewing of internal body regions.
The use of an everting catheter requires the control and manipulation of several different components. For example, movement and control of the inner catheter is required in connection with the eversion and inversion of the everting element, and movement and control of the instrument relative to the inner catheter is necessary in order to properly position the instrument within the body of the patient. In addition, the outer catheter must be properly positioned. Because of these multiple controlling and positioning tasks, the use of an everting catheter system commonly requires two attendants.
Non-everting catheters also may require multiple controlling and positioning functions during use. For example, a non-everting catheter may have an instrument extending through the lumen of the catheter and into the body of the patient. During use, it is commonly necessary to position the catheter and the instrument within the patient; however, unlike everting catheters, only a single catheter needs to be positioned.
Various controllers for manipulating an instrument in a catheter lumen are known. For example, one prior art device, known as a guidewire torquer, includes a collet clamped onto a guidewire which extends through an access catheter or angioplasty catheter. The torquer allows the operator to operate the guidewire about a central axis and move the guidewire proximally and distally. However, the torquer does not control the position of the catheter.
In the field of arthrectomy devices, it is known to use a hand-held controller attached to a guiding catheter. The controller rotates a drive cable or instrument shaft which manipulates cutting surfaces on the distal end of the instrument. The controller has a pull knob which can advance and withdraw the cutting surface of the instrument within the lumen of the catheter. Other controllers of this type rotate an instrument or drive cable which imparts rotational energy to the cutting surface.
Another known controller imparts ultrasonic energy to an instrument shaft which extends through the lumen of a catheter. A controller of this type may also have a pistol-trigger grip which allows an ultrasonic ablative surface to be advanced and withdrawn. Other types of pistol-trigger grip devices which are attached to primary catheters can be used for grabbing forceps or scissors.